Survivors of childhood Bone Marrow Transplant (BMT) are growing in numbers. The intensity of this therapy puts them at risk for long-term complications. The musculoskeletal system is one area where these long term complications may occur. Diminished bone mineral density (BMD) and muscle strength are potential morbidities of BMT. Studies looking at the musculoskeletal system and health related quality of life (HRQOL) in this population have not been conducted. The specific aims of this study include 1. Describe the relationships among BMD, muscle strength and HRQOL as they relate to age, sex, type of BMT, years post BMT, endocrine function and steroid use, in survivors who are at least two years post childhood BMT. 2. Compare the BMD of survivors who are at least two years post childhood BMT to age and sex matched established norms from healthy children. 3. Compare the muscle strength of survivors who are at least two years post childhood BMT to age, sex and size matched established norms from healthy children. 4. Compare the HRQOL of survivors who are at least two years post childhood BMT to established norms from healthy children. [unreadable] [unreadable] [unreadable]